The long-term objective of the project is to provide a basic understanding of ovarian cellular gonadotropin receptor regulation which will eventually be applicable to the problem of fertility regulation. This application is concerned primarily with determining the chemical and biological characteristics of a factor which has been partially purified from platelet-derived growth factor (PDGF) preparations. This material facilitates differentiation by enhancing FSH-stimulated LH receptor induction in granulosa cells. It appears to be a unique species of human Transforming Growth Factor Beta which we are provisionally designating Transforming Growth Factor-Beta-Like Material (TGF-B-LM). To extend these findings, this proposal is concerned with three specific aims: 1) to elucidate the chemical properties of TGF-B-LM by a) purifying it to electrophoretic homogeneity, b) determining the amino acid sequence of the material by gas-phase microsequenator technology, and c) by generating antibodies to TGF-B-LM for application to purification procedures; 2) to investigate the biological properties of TGF-B- LM by a) analyzing in greater detail how TGF-B-LM potentiates FSH-stimulated induction of functional LH/hCG receptor, b) characterizing its growth-promoting or inhibiting properties upon primary cultures of granulosa or cumulus cells and ovarian cancer cell lines and c) utilizing TGF-B-LM and anti-TGF-B-LM immunoprecipitation approaches to determine whether ovarian cells themselves produce TGF-B-LM; 3) to isolate and identify an FSH- and EGF-modulated Mr 27,000 component from porcine granulosa cells and determine its principal physiological role.